
4-193
FAST AND LS TTL DATA
MC54/74F399
FUNCTIONAL DESCRIPTION
The MC54/74F398 is a high-speed quad 2-port register. It
will select four bits of data from either of two sources (Ports)
under control of a common Select input (S). The selected data
is transferred to a 4-bit output register synchronous with the
LOW-to-HIGH transition of the Clock input (CP). The 4-bit D-
type output register is fully edge-triggered. The Data inputs
(I0x, I1x) and Select input (S) must be stable only a setup time
prior to and hold time after the LOW-to-HIGH transition of the
Clock input for predictable operation.
Inputs
Output
S
I0
I1
X
Q
I
I
h
h
I
h
X
X
X
I
h
L
H
L
H
H = HIGH Voltage Level
L = LOW Voltage Level
h = HIGH Voltage Level one setup time prior to the LOW-to-HIGH clock transition
I = LOW Voltage Level one setup time prior to the LOW-to-HIGH clock transition
X = Don’t Care
FUNCTION TABLE
GUARANTEED OPERATING RANGES
Symbol
Parameter
Min
Typ
Unit
VCC
Supply Voltage
54, 74
4.5
5.0
5.5
V
TA
Operating Ambient Temperature Range
54
–55
25
125
°
C
74
0
25
70
IOH
Output Current
High
54, 74
– 1.0
mA
IOL
Output Current
Low
54, 74
20
mA
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE
(unless otherwise specified)
Limits
Symbol
Parameter
Min
Typ
Max
Unit
Test Conditions
VIH
2.0
V
Guaranteed Input HIGH Voltage
VIL
Input LOW Voltage
0.8
V
Guaranteed Input LOW Voltage
VIK
Input Clamp Diode Voltage
–1.2
V
IIN = –18 mA
VCC = MIN
VOH
Output HIGH Voltage
54, 74
2.5
3.4
V
IOH = – 1.0 mA
VCC = 4.5 V
74
2.7
3.4
V
IOH = – 1.0 mA
VCC = 4.75 V
VOL
Output LOW Voltage
0.35
0.5
V
IOL = 20 mA
VCC = MIN
IIH
Input HIGH Current
20
μ
A
VIN = 2.7 V
VCC = MAX
100
μ
A
VIN = 7.0 V
IIL
Input LOW Current
–0.6
mA
VIN = 0.5 V
VCC = MAX
IOS
Output Short Circuit Current (Note 2)
–60
–150
mA
VOUT = 0 V
VCC = MAX
ICC
Power Supply Current
22
34
mA
VCC = MAX
VIN = GND
CP =
NOTES:
1. For conditions shown as MIN or MAX, use the appropriate value specified under guaranteed operating ranges.
2. Not more than one output should be shorted at a time, nor for more than 1 second.